LIDAR

Techmap processes an average of 10,000 square miles of LIDAR data each year. Techmap also can capture LIDAR data, with the range from 500m to 6,000m and accuracies from +/- 15cm to 40cm. Techmap LIDAR experts have used the customized processing methods, which include automated processing of LIDAR data to bare ground, generation of 3D break lines, and the creation of the land-cover/land-use classifications for the calculation of roughness for the features of hydrology. The LIDAR data acquisition and processing capacity enables us to deliver accurate LIDAR map on time for any specialized projects. The products we delivered are DEMs, Contours and Intensity Images. We use a fast method for producing LIDAR DEMs, accurate for use in orthophoto rectification. We offer both bare earth DEMs and reflective surface with a post spacing of 1m to 4.5m. With complemented break-lines, we can provide contours at 2' to 5' intervals, which meets the National Map Accuracy Standards. Geo-referenced LIDAR Intensity Images can be used to remove planimetric features input in the LIDAR data processing and to verify the horizontal accuracy of the LIDAR data.

Digital Imaging

With Leica ADS40 cameras, the digital aerial imagery acquisition can be done at pixel resolutions from 4" (10cm) to 2m, collecting data in panchromatic, red, green, blue, and near-infrared spectral bands in a single flight. Airborne GPS and inertial measurement systems ensure the high accuracy for our data positioning.

Having processed more than 100,000 square miles of ADS40 digital imagery, Techmap offers customers vast digital imaging products, such as orthoimagery, DEMs, contours, planimetric and topographic data. The orthoimagery scales from 1:600 (1" = 50') to 1:12,000 (1"= 1,000'), and the pixel resolutions from 4" (10cm) to 1m. The orthoimagery is available in ground and true orthoimagery format. The robust digital surface model (DSM) data serves to orthorectify each image and is used for 3D visualization and applications. With the use of stereo pairs of the ADS40 imagery, the 3D planimetric and topographic data can be compiled. Then the transportation networks, building footprints, hydrography, and break lines can be collected. A derived bare earth Digital Terrain Model (DTM) with the 3D break lines supports topographic contour generation at 2' to 8' intervals.

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